The present invention is directed to seals for air filters.
More particularly, the present invention is directed to air filters for internal combustion engines having a lip seal which fits around an air outlet pipe.
Heavy duty air filters used with internal combustion engines for trucks and relatively large earth moving equipment and construction equipment currently use lip seals to seal around air outlet pipes through which filtered engine air is conveyed for combustion. In accordance with the current design, an encapsulated rubber end cap has a radial seal portion thereon engaging the outlet pipe. Material costs for current designs are relatively high and manufacturing complications are introduced because the seal and end caps are unitary, made entirely of polyurethane and are both rather soft. Additional manufacturing complications are introduced because the seal area must be cleaned to remove plastisol and other debris, and because silicone grease is applied so that the soft seal will slide over an outlet pipe of the housing in which the filter is mounted. Since both the seal and end cap are made of polyurethane, both are soft. It is desirable to reduce manufacturing costs and complications and to have a seal and end cap configuration which is more robust.
The present invention is directed to an air filter comprising an annular filter element having an annular filter media with first and second ends closed by first and second annular end caps. A gasket is seated within the first end of the filter media in an initial snap fit with the first end cap. The gasket comprises a unitary body of resilient material having a radially extending flange portion for overlying a radially extending portion of the end cap and has an axially extending body portion. An annular outwardly facing groove in the axially extending body portion of the unitary body receives the axially extending portion of the end cap therein to thereby provide mechanical locking of the gasket on the end cap. An internally facing sealing surface is provided on the axially extending body portion for engaging an air inlet pipe and a tapered portion on the unitary body extends from the groove in a direction away from the radial flange for facilitating insertion of the gasket within the first end of the filter media.
In a further aspect of the invention, the gasket is made of rubber, foam rubber or polyurethane, and in still another aspect of the invention, the gasket is secured by adhesive after it is snap-fitted within the first end of the filter element.